Stearic acid (C18H36O2) and palmitic acid (C16H32O2) are common fatty acids. Commercial grades of stearic acid usually contain palmitic acid as well. A 1.115g sample of a commercial-grade stearic acid is dissolved in 50.00 mL benzene ( d= 0.879 g/mL). The freezing point of the solution is found to be 5.072. The freezing point of pure benzene is 5.533 degrees Celsius , and for benzene is 5.12 degrees Cm^-1. What is the mass percent of palmitic acid in the stearic acid sample?